In the building construction laterally disposed wood blocks of a desired thickness are customarily used to establish an offset string line so as to provide a demarcation line for the placement of work materials in the construction of a building.
Customarily, the workmen at the construction site will nail a scrap wood piece of a desired thickness to the structure or at an offset demarcation site (e.g. a pair of vertical posts) properly aligned to provide the appropriate offset demarcation reference point. Most typically, a scrap wood block of a ¾ inch or 1½ inch thickness serves as measurement from the offset line for the placement of work materials upon the structure.
Unfortunately, the use of wood blocks as an offset line mount contributes to increased construction costs, decreased offset line settings reliability and significantly increased working hazards. In order to insure the accuracy of the offset line, the site workers customarily take time to seek or fabricate a suitable wood block free from warp, cracks, knots, grooves or cuts, dimensional undersizing or oversizing, etc., for nailing onto the offset anchoring site. Upon nailing, the nailed wood block becomes a work place hazard and especially after the nailed block has been later removed from its anchoring site. In order to remove the nailed block from the site, the nailed block is customarily pried loose from its anchoring site. Unfortunately, the projecting and exposed nail tip will typically remain firmly anchored onto the wood block, thus creating a hazardous working environment. This can lead to worker injury or death at the work site. The hazards presented by nails projecting from used lumber pieces at the work site has prompted OSHA to issue regulations and fines for failing to remove hazardous nails from scrap lumber at the construction site. This necessitates the site workers to exercise particular care and effort to remove all nails from offset boards used in the offset string lines. The time devoted to removing nails from the wood blocks reduces productive work at the construction site.
Although there has long existed a need for a more effective tool for offset systems in the construction business, the offset line alignment gear and use has remained essentially the same as it existed a century ago. An alignment tool of a durable structure suitable for prolonged and continuous use, easily removable after use, convenient in anchoring and the aligning the tool at the construction site, equipped with graduated alignment guides which affords multiple choices in offset line positioning, an improved guide for retention of the string line during use and a tool sized so as to be easily pocketed and carried by workmen at the work site would afford significant advantages over past tools and practices.